Step-by-step feeding mechanism



2 Sheets-Sheet l J. WALLERIUS ET AL STEP-BY-STEP FEEDING MECHANISM July27, 1954 Filed Aug. 24, 1949 Patented July 27, 1954 ATE NT "OFFICESTEP-BY-STEP FEEDING MECHANISM Application August 24, 1949; Serial No;112,062

1 Claim. l

This invention relates tofeed mechanisms for furnaces andv moreparticularly to feed mechanisms in which there `is both a horizontal anda vertical movement and the movements areso coordinated that `an articlecan-beadvanced through a furnace in a step by step manner.

vHeretofore feed mechanisms of the above cha-racter have not beensatisfactory in all respects. For example one of the objections to priorfeed mechanisms of this character is that they are rather complicated.Too, they have also employed cams foreffecting the Vrespective movementsand because of the stresses involved the cams wear. `As a result uniformhorizontal and vertical movements are not obtained and consequently thearticles are not fed through the furnace properly. Another objection hasbeen that the cams haveV to be replaced frequently. Due to the complexcharacter of feeding mechanisms for prior designs of furnaces the feed rmechanisms are rather diicult to service and consequently themaintenancecosts are relatively high.

Accordingly, an object of this invention is to provide a novel feedmechanism of the above character with means for effecting a positivemovement in bot-h horizontal and vertical directions.

Another objcct of the invention-is to provide a feed mechanism of theabove character that is simple to construct, that permits accessibilityto all moving parts, that is easy to service, and that isrelativelyinexpensive to produce.

Other objects-and advantages ofthe invention will become apparent fromthe following detailed description taken in connection with theaccompanying drawings, in which- Figure 1 is a longitudinal sectionalview of-a furnace embodying the present-'invention with the verticallymovable support means vin a raised position;

liig.2 is a fragmentary view similar to Figure l showing the verticallymovable support means in a retracted position;

Fig. 3 is an endview of Figure 1; and

Fig. 4 is ari-enlarged sectional view taken substantially along'thelines-ll-'d'fof liigure l.

Referring now to the drawings, the Vinvention is shownk embodied in afeed mechanism for al furnace designated generally 4by the vnumeral l l.In generalthe furnace includes a bottom portion l2, sides i3 and Mandatop (not-shown) formed of Vsuitablerefractory material, and defining aheatingrchamber |16^having openings ilY andfl, respectivelyyat thecharge and discharge end of 2 the Vfurnace il. The furnace may be heatedby any suitable means. For purposes of-simplifying the drawingsthelatter has been omitted. Vertically movable doors`2l and 22,respectively, close the openings il and i8. `-The feed mechanism ingeneral comprises carrier means reciprocable between horizontalpositions for moving workpieces i9 horizontally between preselectedpositions and vertically movable support means for supporting theworkpieces-an'dmovable betweena retracted position in which theworkpieces rest on the horizontally movable carrier for movement inunison therewithanda position in which Vthe Workpieces I9 are raisedabove the carrier to permit the Vcarrier to be moved horizontallyindependently of the workpieces I9. Suitable means may be utilized forcoordinating the respective movements of the carrier and vthe supportmeans so that the workpieces are advanced ina step by stepmannerthrough'the heating chamber I6 of the furnacel I l.

As -best seen in Figs. land 4 the carrier means comprises a pair-of linkchainsy 23. The latter are disposed in spaced-troughshaped guideways 26vdisposed lengthwise on the bottoml l2l of the furnace l l.`Preferablythe guideways are formed -of material havinggoodwearresisting qualities,

one such material being Carborundum. At the charge end of the furnacethe chains 23 are supported by spaced sprockets 2 mounted on atransversely extending shaft 28. The latter is supported -byfasuitablesupport 29 mounted on the framework 3| supporting the furnace I I. Theshaft 28 is spaced from the charge'end of the furnace a sufficientdistance so that the portions of the chains 23 between the sprockets 2land the end of the furnace II form a table portion lat the chargeendofthe furnace forrsupporting the workpieces. `After passing over thesprockets 27 the -chains23` are connected to a crossheadd.

The crosshead is connected to one end of a piston (not shown) of -apressure fluid unit 34 by a rod 3S. The pressure fluid unit 34 is shownmounted on the vframework 3i beneath the bottom i2 of the furnace i i.At the opposite end of the furnace the chains 23 are mounted on spacedsprockets 3l (one only being shown) mounted on a transversely extendingshaft 38, the latter being supported Vby a suitable support 39 mountedon the framework 3 i. The shaft 38 is spaced from the dischargeend ofthe furnace a su'iiicient distance so that the portions ofthe chains 23between the sprockets 37 and the end ofthe furnace form Vatable portionfor supporting the workpiecesafter they are 'discharged from thefurnace. After passing over the sprockets 3l the ends of the chains 23are interconnected by a crosshead 4l which in turn is connected to theopposite end of the piston in the pressure fluid unit 3d by a cable 42.A turnbuckle 43 is connected in series with the cable l2 for varying theslack in the chains 23 to permit of adjustment of the tension in thechains 23.

The ow of pressure fluid to the pressure fluid unit 34 is under thecontrol of a suitable conventional control valve unit lift. The latteris connected with opposite ends of the pressure fluid unit SLi byconduits 4t and 4l, respectively, and is connected to a pressure fluidsource by a conduit d8. Inasmuch as any conventional valve unit fifi maybe utilized, for purposes of simplifying the drawings in this instance,the valve unit lili is shown herein by symbol only. With thisconstruction the flow of pressure fluid may be directed to either end ofthe pressure huid unit 3d. Thus, by alternately applying the pressurefluid first to one end of the unit 313 and then to the other end thechains 23 may be caused to reciprocate between opposed positions, thedistance of movement being equal to the stroke of the piston in the unitlill.

The vertically movable support means, in this instance, includes aplurality of vertically disposed uprights 5l extending through openings52 in the bottom i2 of the furnace. The uprights 5! are disposed inalined rows adjacent the side walls i3 and i4, respectively, of thefurnace. Spaced outwardly from opposite ends of the furnace are spaceduprights 53, respectively, in alinement with the rows of uprights 5i.Beams 5d extending between adjacent uprights in each row are suitablysupported to have their upper surfaces disposed in a substantiallycommon plane and to define spaced workpiece supports extendinglengthwise of the furnace shaped to support opposite edges respectivelyof workpieces is being advanced through the furnace. To support thebeams the uprights 53 are formed with caps 56 including a centralportion 5l extending upwardly from spaced shoulders 5d and the uprights5l are provided with caps 5S including a central portion 85 extendingupwardly from spaced shoulders 6ta. The tops of the central portions 5iand the tops of the central portions 'i5 are disposed in a substantiallycommon plane. As best seen in Figs. 3 and 4 the beams 513 have aninverted U-shaped cross section and are arranged so that the bridgingportion of the beamsr rests on the tops of the central portions and theleg portions straddle the central portions. Each of the beams 5s ispivotally mounted at one end and has its opposite end freely supported.Adjacent beams 5d are in spaced endwise relation to allow for expansionof the beams when the furnace is brought up to ternperature. Theuprights 5i are mounted for reciprocation in suitable verticallyarranged guides Gl attached to and depending from the bottom l2 of thefurnace and the uprights 53 are supported in suitable guides d2supported on the framewor 3i at opposite ends of the furnace.

At the bottom of each upright is a toggle joint it. The toggle jointsfor the uprights 5i and 53 are of similar construction. For purposes ofsimplification therefore only one of the toggle joints 'iii will bedescribed in detail. As best seen in Fig. 4 each toggle joint IGincludes spaced bars fit each pivotally connected at one end to a pin51. rlhe latter extends through the upright 5I and projects throughvertically elongated slots B8 formed in the guide fil on opposite sidesof the upright 5l. The opposite ends of the spaced bars 66 arerespectively pivotally connected to one end of spaced bars t as by a pinli. The opposite ends of the spaced bars 65 are pivotally supported on ashaft l2. The latter is supported by suitable spaced supports 'I3mounted on spaced channel irons '.14 forming a part of the framework 3i.The supports 'i3 are disposed in spaced axial relation to the lower endsof the respective uprights. A spacer i6 maintains the lower ends of thebars 69 in spaced relation. The pivotal connection between the spacedbars 66 and 69 forms a knee.

Driving links 'l'i extend lengthwise of the framework 3i below thefurnace ll in alinement with each row of uprights. Each link 'i1 ispivotally connected to all of the knees in one of the rows of uprights.As best seen in Fig. 4 the driving links 'Vi are supported on pivot pinsIl between the spaced bars GS. Spacers i8 position the link Tintermediate the bars 69.

Suitable provision is made for moving the links 'Vi to simultaneouslymove all of the knees of the toggle joints 'iii between opposedpositions on one side of an axis defined by alinement of the bars 55 and59 to raise the uprights to a position in which the top surfaces of thebeams 54 are above the workpiece supporting surfaces of the chains 23and a retracted position in which the top surfaces of the beams 5d arebelow the supporting surfaces of the chains 23. As shown in Figs. 2 and3, at the charge end of the furnace, each driving link "il is connectedto a link li in turn pivotally connected to one end of an arm Si; thelatter is keyed to a shaft 82 supported by suitable bearings, not shown,mounted on vertical members S3 forming part of the framework Si.Intermediate the arms Si is an arm 811 keyed to the shaft 82 and havingits free end pivotally connected to one end of a piston (not shown)mounted in a pressure iiuid unit 8i. The pressure fluid unit in thisembodiment of the invention is under the control of a control valve unit88. The latter is connected to opposite ends of the pressure fluid unitby conduits 89 and 9 i, respectively, and to a source of pressure fluidby a conduit S2.

The control valve units lili and 28 may be provided with a suitabletiming mechanism incorporated in each unit in a conventional manner tocoordinate the movements of the carrier and the support means. Theopening and closing of the doors 2l may also be controlled by the timingmechanisms in the control units so that the doors open and close incoordinated timed relation with the horizontal movement of the carrierand the vertical movement of the supports. Where desired a master timingdevice may be employed for controlling the movements of the carrier andsupports means and the opening and closing of the doors.

The operation of the aforegoing feed mechanism is apparent from theabove description but may be summarized briefly as follows: As shown inFigure 1 the vertically movable supports are in their raised position.With the parts in this position the operator places workpieces i9 on thebeams 5t at the charge end of the furnace. The uprights 5| and 53 arethen moved to a retracted position. This is effected by applyingpressure uid to the pressure fluid unit 8l to cause the arm 84 to rotatein counterclockwise direction as viewed in Figs. l and 2. Simultaneouslythe arm 8| is rotated in a counterclockwise direction and the drivinglinks il are shifted to the left of the position they assume in Figurei. At the conclusion of this shifting movement the links 'il are in theposition shown in Fig. 2 and the uprights are in a retracted position sothat workpieces rest on the chains 23. Simultaneously with theretraction of the support means pressure fluid is applied through theconduit 46 to the left hand end (as viewed in Figure l) of the pressurefluid unit 3Q to eifect movement of the chains 23 through the furnace.This advances the workpieces I9 in the direction of the furnace adistance corresponding to the length of the stroke of the piston in thepressure uid unit 34. At the conclusion of this movement of the chainsthe support means is raised to lift the workpieces I9 above the chains23. This is effected by applying pressure uid to the unit 87 to causethe arm 8B to rotate in a clockwise direction as viewed in Fig. 2.Simultaneously the arm 8| is rotated in a clockwise direction and thedriving links l? are shifted from their position shown in Fig. 2 to theposition they assume shown in Figure 1. During this movement the kneesof the toggle joints are moved to the right. Normally the bars 66 and 69are disposed at an angle to each other. As the knees are moved to theright from the position they have in Fig. 2 they are urged toward aposition of alinement. As they approach alinement the uprights 5I and 53are forced upwardly. The closer the bars approach alinement the greaterthe force applied to the uprights. As soon as the workpieces I9 clearthe chains 26 pressure fluid is applied to the pressure fluid unit 6d ina direction to effect reverse movement of the chains 23 a distance againcorresponding to the length of the stroke of the piston of the unit 36.The. support means is then lowered as described above and so that theworkpieces again rest on the chains 23. Pressure fluid is again directedto the pressure fluid unit 36 to effect forward movement of the chains23 to advance the workpieces farther into the furnace. If it is desiredto advance the workpieces rapidly through the furnace in a step by stepmanner the above cycle is repeated the required number of times to movethe Workpieces the length of the heating chamber I6. In some instancesit may be desirable to leave the workpieces i9 in a particular heatingzone in the furnace for a certain length of time. This may beaccomplished by varying the length of time between operations of thecarrier or the vertical support means. This construction has manyadvantages as are readily apparent to those skilled in the art. It issimple.

The operation of the carrier and supports is positive. Moreover the feedmechanism is relatively inexpensive to manufacture.

While We have shown one embodiment of our invention it Will beunderstood that we do not wish to be limited thereto since manymodifications may be made and we therefore contemplate by the claim tocover such modifications as fall within the true spirit and scope of ourinvention.

We claim:

In a mechanism for feeding an article to a furnace, the combination ofspaced link chains extending horizontally through the furnace, sprocketsat opposite ends of the furnace for supporting the chain, pressure fluidmeans connected to opposite ends of the chains for eiecting reciprocablemovement of the portion of the chain in the furnace between preselectedpositions, a plurality of vertically movable uprights disposed in alinedrows, guide means for said uprights, beams extending between adjacentuprights in each row to define a support means having spaced surfacesshaped to engage opposite edges of an article and movable between aretracted position in which the surfaces are below the top of the chainsand a raised position in which the surfaces are above the top of thechain, said beams being arranged in end to end relationship with a spacebetween adjacent ends thereof, a first bar pivotally connected to eachupright, a second bar pivotally connected to each of said first bars,means for pivotally mounting the opposite end of each of said secondbars to be in substantially alined relation with said uprights and to beat one side of the connection between the first and second bars, adriving link for each row of uprights pivotally connected to each firstand second bar in each of said rows, and pressure fluid means connectedto said links for moving said bars between a position in which the barsare out of alinement and said spaced surfaces are in their retractedposition and a position in which they approach alinement to effectvertical movement of the spaced surfaces of said support means to theirraised positions whereby upon successive reciprocations of said chainsand said support means the article is advanced through the furnace in astep by step manner.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 553,315 Packer Jan. 21, 1896 665,227 Johnston Jan. 1, 19011,686,696 Hirshmann Oct. 9, 1928 1,861,492 Culbertson June 7, 19321,871,501 De Coriolis Aug. 16, 1932 2,416,763 Lynch Mar. 4, 1947

